London has been battered by 50mph winds that have felled trees and caused travel chaos. Powerful gusts swept across the capital as the Met Office issued a yellow "be aware" weather alert for most of the country.

David Cameron has denied that Government proposals to monitor calls, emails, texts and website visits would be a "snoopers' charter".

The Prime Minister insisted the moves were needed to keep up with changes in technology and were vital in the effort to tackle serious crime and terrorism.

Deputy Prime Minister Nick Clegg said the controversial proposals would be published in draft form for consultation and would include the "highest possible safeguards".

The Government has faced a backlash from Tory and Liberal Democrat backbenchers concerned at the erosion of civil liberties. Both parties had previously condemned the Labour government's plans to establish a surveillance database.

Asked why the Tories appeared to have changed their position, Mr Cameron said: "Let's be absolutely clear, this is not what the last government proposed and we opposed. And let's be clear, this is not about extending the reach of the state into people's data, it's about trying to keep up with modern technology.

"But we should remember that this sort of data, used at the moment, through the proper processes, is absolutely vital in stopping serious crime and some of the most serious terrorist incidents that could kill people in our country, so it's essential we get this right. Yes to keeping up with modern technology. No to a snoopers' charter."

Labour leader Ed Miliband said the Government had "spectacularly mishandled" a sensitive issue. He said: "It is always going to lead to fears about general browsing of people's emails unless they are clear about their proposals, clear about what they would mean, clear about how they are changing the law."

Liberal Democrat MP Julian Huppert, who sits on the Home Affairs Select Committee, warned there were real questions to answer about the technological capability of any new system. He said: "Proposals to read exactly what we write in an email would, I think, be totally unacceptable.

"I think from a principle level I'm not wild about phone records being kept but it's hard to see whether there is a difference between a phone record and a Skype record. But there are key problems from both a technological and a cost point of view."

Home Secretary Theresa May said the proposed law change, which will mean internet companies are instructed to install hardware tracking telephone and website traffic, would help police. She will face questions about the plans when she appears in front of the Home Affairs Select Committee on April 24.